Perl regex question

Shell Programming and Scripting
1 
$var=~ s#(\n?<a>.*?</a>\n)##s
$pat=$1

Recently i came across this bit of a code.
Can someone please explain the function of these two line?

2

Appears to removing anything between the <a> and </a> tags in an html file in the first line.

The next line that uses $1 assigns the value that matches the pattern is assigned to pat. In this case it assigns to pat what is being removed.

3

Seems like it removes the first occurrence of the substring that matches the pattern:

newline, followed by <a> </a> tags and the minimal text between them, followed by newline

from the variable $var. And then assigns the substring (that matched the pattern) to the variable $pat.

tyler_durden

4

Thanks a lot for ur replies. But I have one more doubt.
Are the #'s being used as delimiters here? If so then what is the purpose of ## at the end of it all?

5

Check out the perl operators documentation (perlop) at Perl version 5.10.0 documentation - perldoc.perl.org. It has a very nice and detailed explanation of the substitution operator, besides other things.

Hope that helps,
tyler_durden

6

Ummm ... sorry but I still could not find an explanation for these #'s ... Could someone please explain it to me?